The present invention relates to acoustical diffusing and absorbing cinder blocks. Acoustic diffusors are known per se. In this regard, reference is made to the following patents issued to co-applicants D'Antonio and Konnert: U.S. Pat. Nos. D291,601 issued Aug. 25, 1987, 4,964,486 issued Oct. 23, 1990 and 5,027,920 issued Jul. 2, 1991. Furthermore, co-applicants D'Antonio and Konnert are also applicants in U.S. Pat. No. 4,821,839 issued Apr. 18, 1989 which discloses a sound absorbing diffusor using the quadratic-residue number theory as well as sound absorbing materials to absorb sound in a controlled manner. Applicants D'Antonio and Konnert are also patentees of U.S. Pat. No. D306,764 which is directed to an acoustical diffusor having a plurality of wells of approximately square cross-section.
While U.S. Pat. Nos. 4,964,486 and 5,027,920 describe acoustical diffusors made of cinder blocks, these references fail to include various aspects of the present invention including the use of a third overlapping locking block, the use of reinforcing rebar and the provision of low frequency sound absorbing chambers.
Further, Applicants are aware of a product sold under the Trademark "SOUNDBLOX" which resembles cinder blocks and which includes slots therein not made in accordance with the number theory sequences. While "SOUNDBLOX" are provided for sound absorption purposes, they have no disclosed or intended sound diffusing characteristics. They include narrow openings allowing entry into internal chambers designed to absorb sound and control reverberation. While such structures, generally speaking, are incorporated in the present invention, the present invention contemplates devices which also include important diffusing characteristics.